There are known in the prior art many forms of mat or carpet products which are intended for growing lawns and other forms of vegetation. These products generally include some sort of fibrous material which provides structural integrity to the mat, and a mulch material which is often mixed with the seeds to be germinated. These products also include some form of joining these various materials together, including stitching, adhesives, and the like. Generally speaking, these products have not gained wide acceptance due to failures in some aspects of their designs.
For example, most mulch material used in these products expands upon watering. Often, the expansion of the mulch material breaks whatever bond is provided with the fibrous structural material of the mat, with the result that significant portions of the mulch and seed mixture are washed away from the mat. Stitching methods for joining the materials to form a mat tend to limit the expansion of the mulch material, forming an irregular surface and also decreasing the survival rate of the germinating seeds.
Also, many of the prior art mat products fail to protect properly the seeds during the germinating and sprouting periods. As the seeds are covered only by a thin layer of mulch material, they are prey to birds and the deleterious effects of strong sunlight. Furthermore, these products often require frequent watering to prevent dehydration of the seed and seedlings, since the water retention capacity of the thin mulch layer is low. The prior art mat products are also subject to lift forces generated by winds of at least moderate strength. Often wind pegs must be used to stake down the mat, later to be removed before mowing. The labor involved is thus duplicated in time and expense.